ON THE GEOMETRY AND DESIGN OF FOUR BAR LINKAGE MECHANISMS

Machines and mechanisms are used wherever it is necessary to replace human work. Many machines (engines, machine tools, agricultural machineries, packaging and automatic machineries, …), require devices that should exhibit certain movements prescribed by technology of working processes. The generation of desired motion of a point-the locus of a point-has been long studied in mechanics. By choosing proper link lengths and coupler point location, useful curves can be found, which were formalized by applying geometry to the analysis and synthesis of machines. Reuleaux’s theories about machines, based largely on geometric ideas and not on dynamic principles, are useful in the kinematic analysis and design of a mechanism which requires information on the changing geometry during motion. From the time of Watt, the generation of straight-line paths has been widely studied and many mechanisms describing straight lines have been classified according to their description of an exact or an approximately-so straight line. For understanding the working of four bar linkage mechanisms, authors designed different simulations by using the Geogebra software.